Action

action, in theoretical physics, an abstract quantity that describes the overall motion of a physical system. Motion, in physics, may be described from at least two points of view: the close-up view and the panoramic view. The close-up view involves an instant-by-instant charting of the behaviour of an object. The panoramic view, on the other hand, reveals not only a complete picture of the actual behaviour of an object but also all the possible routes of development connecting an initial situation with a final situation. From the panoramic view, each route between the two situations is characterized by a specific ... (100 of 325 words)